c作业

1.#include<stdio.h>

void main(){

         intcount1,count2,count3,count4;

         inti;

         charstr[40]="auaho;iHldvaco 684+n**(79(#";

         for(i=0;i<40;i++)

                  if((str[i]>='a' && str[i] <= 'z') || (str[i] >= 'A' && str[i]<='Z')){

                          count1++;

                  }

                  elseif(str[i] >= '0' || str[i] <= '9'){

                          count2++;

                  }

                  elseif(str[i]==' '){

                          count3++;

                  }

                  else{

                          count4++;

                  }

        

        

        

         printf("英文字母的个数为:%d",count1);

         printf("数字的个数为:%d",count2);

         printf("空格的个数为:%d",count3);

         printf("其它字符的个数为:%d",count4);

 

}

 

2.#include<stdio.h>

void main(){

         floatresult=0.0;

         intn;

         for(n=1;n<100;n++){

                  result+=(float)1/(n*(n+1));

         }

         printf("最后的结果为:%f",result);

}

3.#include<stdio.h>

void main(){

         inta[3][2]={{2,4},{6,9},{12,8}};

         intb[2][3],i,j;

         printf("数组a:\n");

         for(i=0;i<=2;i++){

                  for(j=0;j<=1;j++){

                          printf("%4d",a[i][j]);

                          b[j][i]=a[i][j];

                  }

                  printf("\n");

         }

         printf("数组b:\n");

         for(i=0;i<=1;i++)

                  for(j=0;j<=2;j++){

                          printf("\n");

                  }

}